Pep Guardiola is obsessed with Lionel Messi but is restricted in how he can stop him

Pep Guardiola works from his office at the Bayern Munich's Sabaner Strasse training base. That is where he trains his team and it is in his office where he analyses rivals, watched DVDs of matches, looks for ways to win games and, in his own words at the Catalan Parliament in 2011, where his work as a coach takes on a greater meaning.

He has a restless nature anyway, but Guardiola is especially busy this season because of injuries, which have shown no signs of slowing up over the last week with both Robben and Lewandowski picking up knocks. Guardiola laments all the absences (Alaba and Badstuber, too) and the also the lack of rhythm of the players just coming back from injuries (Javi Martinez and Ribery) have.

Also, it's hampered his ability to rotate throughout the season, which has not cost them in the the Bundesliga, but did contribute to them being knocked out of the cup. He understands that these circumstances will work as a disadvantage in the semi-final of the Champions League. This is the first time he will play at Camp Nou as the visitor and he would have liked to have been able to approach the game in a better position.

Now, more of a pessimist by nature, he's more concerned than he might have been. But Pep is Pep and he can certainly invent something because nobody knows the virtues and defects of the Barcelona players like he does. With him in charge they were great. 

There are three aspects that worry him and one that he is obsessed about: There was another demonstation of Guardiola's admiration for Lionel Messi as he watched Barça's game with Manchester City from his Camp Nou seat. For several days now he has been thinking: How to stop Messi? How to reduce his space? How to disconnect him?

These are questions which Pep used to force rival coaches to think about, now he must answer them on Wednesday. 

What the Bayern coach is most upset about is the absence of David Alaba. The left-back has been out since for a while with ligament damage and he would have been the ideal man to face up to Messi, but instead it's likely to be Juan Bernat, who has different characteristics. 

Bernat does know Messi -- he's played against him two times before -- but he will need help from the likes of Lahm and Boateng. That will be key. 

From the obsession with stopping Messi, Guardiola also has worries in attack. Lewandowski comes into the match with a broken jaw and a broken nose and a late decision will be taken on him, but Pep isn't overly concerned because he has alternatives (Müller and Götze).

He is more concerned about the absence of Robben, because before his first injury five weeks ago he was in splendid form. Above all, he is the one player in Bayern's squad who can beat a man one on one and who is capable of unbalancing Barcelona's defence. 

At the same time, Guardiola also wants the emphasis to be on his players keeping the ball. The objective is to take the ball off of Barcelona, even though experience proves that is not the key to winning. That was proved when Heynckes' Bayern eliminated Barça 7-0 in 2014 with 37 percent possession in the first leg and 43 percent in the second leg. 

Barça and Bayern, as of today, are two teams with identical possession stats, the cream of the Champions League (62 percent possession and 91 percent pass accuracy). 

Analysing the teams, Guardiola sees a new handicap for the tie. His best player at the moment is Thiago, who is fresh and hungry after missing so much time through injury. The former Barça player was key to the win against Porto and will be key at Camp Nou. 

For Pep, the best Barça player is Messi. The difference between Thiago and Messi is that one creates danger around the area and the other, because of his position on the pitch, is too far away from the goal. Another argument for thinking negatively.